UMTS (Universal Mobile Telecommunications System) is one of global 3G standards stipulated by the International Organization for Standardization 3GPP (3rd Generation Partnership Project). In Release-5, an HSDPA (High Speed Downlink Packet Access) technology is introduced to increase a downlink data transmission rate and reduce a delay of user data transmission, so that a user has better experience in a UMTS network.
A physical layer working principle of the HSDPA technology introduced in Release-5 is as follows: a NodeB (base station) sends data to a UE (User Equipment) through an HS-PDSCH (High-Speed Physical Downlink Shared Channel) at a physical layer, and in addition, sends HS-PDSCH-related control signaling and the like through an HS-SCCH (High-Speed Shared Control Channel. After receiving the HS-SCCH, the UE performs demodulation, decoding, and the like on the HS-PDSCH by using control information carried on the HS-SCCH, and then the UE generates ACK (Acknowledgement)/NACK (Negative Acknowledgement)/DTX (Discrete Transmission) information according to a reception condition of the HS-SCCH and whether the HS-PDSCH is decoded correctly. In addition, the UE further measures a downlink channel condition and generates CQI (Channel Quality Indicator) information, the UE carries the ACK/NACK/DTX information and the CQI information on an HS-DPCCH (Dedicated Physical Control Channel (uplink) for HS-DSCH) and sends the ACK/NACK/DTX information and the CQI information to the base station, and the base station uses information fed back by the UE as a basis for service scheduling. The HS-DSCH (High-Speed Physical Downlink Shared Channel) belongs to a transmission channel at a MAC (Medium Access Control) layer in a communications protocol, and is mapped as the HS-PDSCH and the HS-SCCH at the physical layer.
Multi-carrier HSDPA technologies are successively introduced in Release-8 and later releases, and data may be concurrently sent to a UE by using multiple downlink carriers (cell). When the data is concurrently sent to the UE by using the multiple downlink carriers (cell), there is a problem of relatively low utilization efficiency of an HS-SCCH code channel resource. For example, when the HS-SCCH is sent, in an existing protocol, the HS-SCCH is independently sent on each carrier. It is assumed that there are four carriers in total, and a quantity of HS-SCCHs that are configured by a network side device for the UE and to which the UE needs to listen is 4; in this case, to support transmission over four carriers, it is required to configure one HS-SCCH on each carrier, that is, scheduling can be performed for a maximum of one UE on each carrier at a time.